In conventional hand pallet trucks, a pole is used to steer and move the vehicle, as well as to pump for lifting a load. To operate the lifting apparatus, especially to lower the load, an operating element is required which should be easily accessible, and allow switching between the functions of lifting and driving as well as sensitive lowering of the load.
Easy accessibility of the operating element is especially important for effective operation of the hand pallet truck when pulling the vehicle, i.e. when the pole is an inclined position in front of the vehicle. By contrast, actuating the functions with an upright pole, i.e. when the vehicle is being pushed, is less important, because in most cases the vehicle is drawn out of the pallet, thereby returning the pole into the inclined position.
For pumping and moving the vehicle, it is advantageous if the pole handle is centrally grippable in order to avoid unnecessary steering as well as frictional forces. As the same time, the actuating forces at the operating element should be as small as possible in all situations requiring a longer actuating path, which might be realized by providing a longer distance between the circle point and the lever pivot point, for example.
It is known to use an extension of the pole bar traversing the handle as a mounting component for an operating lever extending to the sides. This known pole handle has the drawback that it cannot be gripped centrally. From DE 297 10 503 U1, it is further known to pivotally mount a control lever as the upper end of the portion of the bar extending into the handle. The lever must be pushed away from the operator to achieve a lowering of the load. Pulling the lever towards the operator will result in a switch to the lifting function. A drawback of this design is that the operator cannot actuate the functions well while pulling the vehicle because the control lever has to be pulled upwards to achieve a lowering action. Further, since the operating element is not familiar from other technical devices, it is less suitable for intuitive operation. The actuating forces are great due to the small distance between the circle point and the lever pivot point.
Apart from the above described possibility of operating a hand pallet truck, it is also common to provide it with an integrated handbrake. In this context, it is known from EP 1 186 511 A2 to pivotally mount an operating lever on either side of a holding extension traversing the handle of the pole in prolongation of the pole. One operating lever is connected to a traction or pushing element for the lifting apparatus and the other one with a traction or pressure element for a brake. Actuation of the lifting apparatus is effected such that pulling of the operating lever initiates a lowering operation in the lifting apparatus while pushing the lever opens up the possibility to effect a lifting operation by pumping on the pole. Pushing the other operating lever leads to braking of the vehicle wherein the extent of the pivotal movement determines the braking power. This known arrangement further provides for a locking/unlocking lever which is also pivotally mounted on the holding extension and has a projection cooperating with a recess of the brake operating lever when the brake operating lever has reached a given hind position. Thus, a parking brake is created which is released by pivoting the locking and unlocking lever in the opposite direction. Thereby the brake operation lever may return to its initial position by means of spring bias from the direction of the brake. Finally, the known arrangement also provides that the parking brake is released by actuating the other operating lever. In other words, when actuating the lowering operation, the parking brake is automatically released.
In the hand pallet trucks described above, the brake is usually optional. Depending on whether a brake is present or not, different handle arrangements have to be provided, thereby complicating the production process.
An object of the invention is to configure the pole head in a pole for a hand pallet truck such that it may optionally receive a brake operating device. When no brake is present, an especially ergonomic actuation of the lifting apparatus is desired.